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Basic Outline of the Law of Polygraphs

David L. Faigman
U.C., Hastings College of the Law

  1. Employment Screening
    1. Employee Polygraph Protection Act (EPPA). 29 U.S.C.A. § 2001 et seq.
      1. § 2002. Prohibits Lie Detector Use for Any Employee or Prospective Employee, subject to exemptions of § 2006 and § 2007.
      2. § 2006. Exemptions.
        1. Governmental employers;
        2. National defense and security exemption;
        3. FBI contractors exemption;
        4. Limited exemption for ongoing investigations;
        5. Exemption for security services;
        6. Exemption for drug security, drug theft, or drug diversion investigations.
      3. § 2007 Restrictions on Use of Exemptions.
  2. Rules of Admissibility
    1. Frye v. United States, 293 F. 1013 (D.C.Cir. 1923).
      1. Qualifications
      2. General Acceptance in the Particular Field
      3. Worthy of Note.
        1. Frye test is deferential to identified field;
        2. Many problems associated with identifying pertinent field;
        3. Requires relatively little scientific sophistication among judges;
        4. NAS composition and committee report likely to be influential under Frye test.
    2. Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).
      1. Qualifications;
      2. Relevance (or "fit"): does the research generalize to the case at hand?
      3. Evidentiary Reliability (i.e., Scientific Validity):
        1. Testability ("falsifiability") and tests done;
        2. Error Rate;
        3. Peer Review and Publication;
        4. General Acceptance.
      4. Worthy of Note.
        1. Test is non-deferential in theory, somewhat deferential in practice;
        2. Daubert requires relatively high scientific sophistication among judges;
        3. NAS committee's analysis is likely to be highly influential.
  3. Admissibility of Polygraph Evidence.
    1. Large number of jurisdictions (including military courts) employ a per se rule excluding polygraph tests.
      1. Worthy of Note.
        1. Courts' primary objections to polygraph:
          1. unreliable;
          2. invades province of the jury;
          3. overwhelming influence on jury.
        2. Per se rule of exclusion does not violate Sixth and Fourteenth Amendment rights to present evidence. U.S. v. Scheffer, 523 U.S. 303 (1998).
      2. Some jurisdictions employing the per se rule allow polygraph tests to be admitted by stipulation of the parties (see C below).
    2. Many jurisdictions allow polygraphs pursuant to the discretion of the trial court.
      1. Popular approach under Daubert
      2. In practice, most courts exclude polygraph testimony under this approach.
    3. Admissible by Stipulation.
      1. Parties must agree to circumstances of test and its subsequent admissibility.
      2. Basis for rule:
        1. More reliable results (e.g., not a friendly examiner; greater fear associated with outcome);
        2. Examinee knowingly assumes the risk (i.e., function of adversary process).
    4. Confessions before, during and after polygraphs are generally admissible.
    5. Constitutional Issues.
      1. Per se exclusion of polygraphs is not unconstitutional, U.S. v. Scheffer (above).
      2. Prosecutor's use of polygraph (pursuant to local rules) generally not considered to raise constitutional issues.
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